title: Passive vaccination with a human monoclonal antibody: generation of antibodies and studies for efficacy in Bacillus anthracis infections.
abstract: A major difficulty in creating human monoclonal antibodies is the lack of a suitable myeloma cell line to be used for fusion experiments. In order to create fully human monoclonal antibodies for passive immunization, the human mouse heteromyeloma cell line CB-F7 was evaluated. Using this cell line, we generated human monoclonal antibodies against Bacillus anthracis toxin components. Antibodies against protective antigen (PA) and against lethal factor (LF) were obtained using peripheral blood lymphocytes (PBLs) from persons vaccinated with the UK anthrax vaccine. PBL were fused with the cell line CB-F7. We obtained several clones producing PA specific Ig and one clone (hLF1-SAN) producing a monoclonal antibody (hLF1) directed against LF. The LF binding antibody was able to neutralize Anthrax toxin activity in an in vitro neutralization assay, and preliminary in vivo studies in mice also indicated a trend towards protection. We mapped the epitope of the antibody binding to LF by dot blot analysis and ELIFA using 80 synthetic LF peptides of 20 amino acid lengths with an overlapping range of 10 amino acids. Our results suggest the binding of the monoclonal antibody to the peptide regions 121-150 or 451-470 of LF. The Fab-fragment of the antibody hLF1 was cloned in Escherichia coli and could be useful as part of a fully human monoclonal antibody for the treatment of Anthrax infections. In general, our studies show the applicability of the CB-F7 line to create fully human monoclonal antibodies for vaccination.
authors.affiliation: Institut für Molekulare Medizin und Zellforschung, Universitätsklinikum Freiburg, Freiburg, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: vor dem Esche
authors.forename: Maria
authors.initials: M
authors.lastname: Huber
authors.forename: Andrea
authors.initials: A
authors.lastname: Zgaga-Griesz
authors.forename: Roland
authors.initials: R
authors.lastname: Grunow
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Beyer
authors.forename: Ulrike
authors.initials: U
authors.lastname: Hahn
authors.forename: Wolfgang G
authors.initials: WG
authors.lastname: Bessler
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000881:Anthrax / Q000276:immunology* / Q000517:prevention & control; D000907:Antibodies, Bacterial / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D000942:Antigens, Bacterial / Q000276:immunology / Q000378:metabolism; D001408:Bacillus anthracis / Q000276:immunology* / Q000472:pathogenicity; D001427:Bacterial Toxins / Q000276:immunology / Q000378:metabolism; D001428:Bacterial Vaccines / Q000008:administration & dosage*; D002459:Cell Fusion; D003001:Cloning, Molecular; D018604:Epitope Mapping; D006801:Humans; D006825:Hybridomas; D007140:Immunoglobulin Fab Fragments / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000276:immunology / Q000378:metabolism; D014611:Vaccination
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D007140:Immunoglobulin Fab Fragments; D010446:Peptide Fragments; C030325:anthrax toxin